Add oldIE Stylesheet

I put together a stylesheet based on the work of @doublex, with some small modifications. These styles should only be applied on IE<8, as they will probably break newer browsers. I also incorporated my solution to the poster width problem (#272). This should resolve #509 and 539 if it works for everyone (I've only been able to do limited testing on a virtual machine running Vista and IE7).

The main problem right now is that I can't get the play button to change to pause when the video is playing. I'm willing to live with it, but it would still be nice to have that working.